Robert smallwood



(No Model.)

R. SMA'LL'WOOD.

STEAMBOILB.

No. 599,200. Patented Feb. 15,1898.

NITED STATES ATENT OFFICE.

ROBERT SMALLVOOD, OE-TRURO, CANADA, ASSIGNOR OF ONE-HALF TO GARDNER CLISH, DUNCAN MCDONALD, AND SILAS R. TUPPER, OF

SAME PLACE. Y l

STEAIVIFBO'ILER.

SPECIFICATION forming part Of Letters Patent N0. 599,200, dated February 15., 1898. Application led July 22, 1897. Serial No. 645,529. (No model.) Patentedin Canada November 20, 1896, No. 54,]1427.

new and useful Improvements in SteamBoil` ers, of which the following is a specication, and for which I received Letters Patent in Canada November 20, 1896, No. 54,127.

My invention relates to improvements in steam-boilers known as the Scotch .or ma.

. rine. boiler, in which the fire-box and combustion-chamber extend nearly the whole length of the boiler and are surrounded by water when in use and have return-tubes extending from the combustion-chamber to the front end of the shell of the boiler; and the objects of my invention are, first, to produce a boiler having the maximum of steam-generating power attainable in a given shell obtained by a method of construction that will admit of a larger nre-box (and consequently increased space for fuel) than can be acquired by any other method of constructing this class of boilers secondly, to obtain better facilities for feeding fuel into the furnace, so that full advantage can be taken of the enlargement of the lire-box. I attain these objects by the form of construction illustrated in the accompanying drawings, in whichm Figure l is a central horizontal section of a boiler embodying my invention. Fig. 2 is a half-elevation of the tube-sheet of the combustion-chamber D. Fig. 3 is a half-elevation of the tube-sheet o f the boiler. Fig. 4 is afront elevation of the boiler, showing the doors and a portion of the smoke-pipe.

Similar letters refer to similar parts through-- out the several views.

In the drawings,- o o o is the shell .of the boiler. 4 Bis the cast-iron front,containing the doors. C is the lire-box. D is the combustion-chamber.- e e e e are're-tubes, which, with the combustion-chamber D and the f1rebox C, are surrounded by water. b a is the tube-sheet of thecombustion-chama is the tube-sheet of the boiler. g g is the smoke-box.

d is the feed-door.

c is the supplementary feed-door.

fis a spiral spring which holds the door c in the desired position, either open or shut.

h is a 'door for the admission of air and for the removal of ashes.

'it' are the tube-doors to admit of ingress to the smoke-box for the purpose of cleansing the tubes and to facilitate their removal or repair. .i

In boilers of this class to allow a sufficiency of Water-space around the combustion-chamber it is necessary for it to be several inches less in diameter than the diameter of the 'shell, and as the rear ends of both the lirebox and tubes are connected into the front side or tube-sheet of the combustion-chamber it necessarilyfollows that the space allowed for the tubes and fire-box is governed by the size of the combustion chamber. As this class of boilers has been usually constructed, the nre-box is parallel, of cylindrical form, and the tubesrun parallel to the fire-box, causing an unnecessary amount of waterspace between the outer tubes and the shell of the boiler and an insufficient fuel-space in the fire-box in comparison with the'size of the shell.

In my invention the mass or body of the fire-tubes el c e e, dro., on each side of the'firebox C are madel to diverge from the center line of the shell to such an extent that the position of their front ends in the tube-sheet d is as close to the circumference of the boiler as they can be conveniently inserted. The fire-box C is then enlarged in diameter as it approaches the front end of the shell to the extent permitted by the divergence of the tubes. be accomplished in detail in various Ways, but all embodying the principle of enlargement toward the front end to the extent practically permitted by the divergence'of the tubes.

To accomplish the second object'of my invention, which is to facilitate the process of feeding the furnace and thus take advantage of the enlargement of the re-box C, there is provided, besides the usual feed-door d, opening sidewise, a supplementary feed-door c, the upper part of which is as high as the re- .box-will permit of. This door is hinged, pref- This enlargement of the fire-box may.

IOO

sheets, and their inn er ends inclined inwardly toward the center of the boiler, and the smokebox g upon each side of the front end of the iire-box, combined with the front B, provided with doors il for the smoke-box, and the two doors c,d, moving at right angles to each other; With the hre-box, and the springf for holding the door c either open or shut, substantially as set forth.

ROBERT SMALLWOOD.

Witnesses F. SMALLWOOD, GARDIE CLIsH. 

